A group of 19 Democratic state attorneys general filed a lawsuit in federal court Thursday to stop the Trump administration’s rollback of an Obama-era regulation intended to protect student loan borrowers.

Led by Massachusetts Attorney General Maura Healey, 18 states and the District of Columbia allege that Education Secretary Betsy DeVos’ decision to delay and eventually replace the so-called “borrower defense” rule violates the Administrative Procedure Act, because the department did not engage in a public notice and comment process in making the decision. Thursday’s lawsuit was filed in the district court in D.C., though Healey warned of the looming legal fight last month. The rule was supposed to go into effect July 1.